British Prime Minister Theresa May said it is time to say "enough is enough" when it comes to tackling terrorism, after seven people were killed and dozens injured in a terror attack in London.

May announced on June 4 that the country's counterterrorism strategy would be reviewed, saying, "We cannot and must not pretend that things can continue as they are."

Police later said 12 people were arrested in Barking, east London, in connection with the June 3 attack, adding that searches in the area were continuing.

A van hit pedestrians on London Bridge at around 10 p.m. local on June 3, then three men got out of the vehicle and stabbed people in nearby Borough Market before being shot dead by police.

No group has so far claimed responsibility for the terror attack -- the third in Britain since late March following a similar attack on March 22 near Parliament on Westminster Bridge and a bombing at a pop concert in Manchester on May 22.

Earlier on June 4, the chief of London's police force, Cressida Dick, said seven people had died in the latest attack, raising the toll from six victims.